What is the difference between regular HDD's, X-Box HDD's, and PS2 HDD's???

[Metallica_Band]

Hey there...I know there is a way to buy a regular HDD and upgrade the X-Box HDD, but is there a way to do the same for the PS2??? What is the difference between the 3 HDD's??? Is it just the preinstalled software or something??? How would one go about upgrading the HDD's in these 2 consoles??? THANX
C'YA

 

[StrongBadia]

Xbox hd's are the same as pc hd's. They just have a special file system.